Prior art Surface Effects Vehicle skirts have been generally large unitary bag-like appendages which were inflated to retain the cushion air. The bag-cell incorporated large amounts of air volume within the bags which would not easily move out of the way of obstacles. They were also virtually incapable of deflating in order to reduce drag across obstacles. The bag-cell was adapted by extending less rigid segments of material which were fixed to each other and arced into the cushion to reduce drag but maintain the air cushion. For an example, see U.S. Pat. No. 3,770,079 issued on Nov. 6, 1973 to Wheeler et al.
Another approach to the air cushion vehicle attempted to permit localized deflation of the air cushion containing skirt by providing multiple cell arrangements which are attached across the underbody of the craft. While permitting localized deflation this concept increased drag by increasing the number of skirts that would have to pass over an obstacle. Sophisticated and complex mechanisms had to be devised to selectively retract individual cushions of the multiple cushion arrangement as shown by U.S. Pat. No. 3,515,238 issued on June 2, 1970 to Knuth et al.
Clearly a skirt was needed which reduced drag and skirt wear due to passage over obstacles. It was also desirable that the skirt be as compliant to the terrain as possible so that the vehicle would be habitable for extended periods and so that the skirt would minimize air escape from the cushion.